The invention relates to a labelling apparatus and a labelling process for the labelling of containers as well as a plant for the treatment of containers.
A plant, which comprises in combination a stretch blow-moulding apparatus, a labelling apparatus and a filling apparatus as a block design, is being tested at present by the Applicants.
In a plant of this type, pre-forms are blow-moulded to form bottles in a first treatment step which is carried out by the stretch blow-moulding apparatus. The bottles are labelled in a second treatment step which is carried out by the labelling apparatus. The bottles are filled and closed in a third treatment step which is carried out by the filling apparatus.
The problem arises in this case that the process sequence can have faults during the first treatment step, in particular in the start-up of the plant, but also when the process is under way. A fault of this type is for example that a pre-form is riot heated to an adequate degree. As a result, the bottle blow-moulded from the insufficiently heated pre-form is defective. In consequence, the defective bottle is separated out before being supplied to the second treatment step. As a result a gap occurs in the otherwise continuous flow of bottles between the stretch blow-moulding apparatus and the labelling apparatus.
In normal operation the labelling apparatus cuts individual labels, which are arranged one behind the other on a strip of labels, from the strip of labels by means of a cutting device. Alternatively, the labelling apparatus can also detach adhesive labels from a carrier strip. This means that the individual labels are arranged one after the other, and no gap occurs in the size of a label In this case, after a label has been separated from the strip of labels, the labelling apparatus applies it in each case to the bottle by means of a labelling device. In normal operation, therefore, the labelling apparatus is set up in such a way that the bottles are supplied to it in a continuous manner. A labelling apparatus of this type is described for example in EP 2 042 437 A1, DE 33 04 191 C2, DE 10 2006 043 260 A1 2008.03.27 or WO 2008/071293.
If, in the case of the plant currently being tested, a gap occurs in the otherwise continuous flow of bottles between the stretch blow-moulding apparatus and the labelling apparatus on account of the above-described fault in the stretch blow-moulding apparatus, the problem arises that the labelling apparatus is set up in normal operation in such a way that it would apply a label to a bottle not present or to a gap between the bottles.
Consideration has therefore been given to providing the labelling apparatus of the plant—currently being tested—with a control device which is intended to prevent a label being dispensed to a gap between bottles which are supplied from the stretch blow-moulding apparatus to the labelling apparatus. To this end it is possible for the control device to be designed in such a way that it can bridge individual gaps by a stoppage of the endless strip of labels, since the continuous dispensing of labels is interrupted by this. In order to re-set the continuous running of the labelling apparatus again, however, after a gap —depending upon the nature of the material of the label —the control device requires a period of time which corresponds to the supply of a plurality of bottles in succession to the labelling apparatus.
In addition, it has been recognized during the testing that when a combination of a plurality of gaps/bottles/gaps/bottles are supplied in succession to the labelling apparatus the risk arises that the re-setting of the labelling apparatus will no longer operate and the strip of labels will be torn. Such a situation can lead to the stoppage of the labelling apparatus and the plant and thus of the entire process, and this results in a corresponding reduction in efficiency of the plant and an unacceptable loss of material.
In addition, there is the problem that an automatic gluing of strips of labels, which is necessary to ensure a continuous operation of the labelling apparatus and thus also of the block plant described above, does not operate in a reliable manner with a high degree of efficiency of the block plant. A reliable gluing would make a slowing-down necessary during the gluing phase, but this is not feasible with the quality of the containers produced by the stretch blow-moulding apparatus. As a consequence thereof the entire block plant would then have to be stopped, but this results in a reduction in efficiency.
As a solution to this problem, consideration has been given to using a labelling apparatus in conjunction with a separate labelling magazine, possibly even without gluing. It would then also be possible for a second labelling apparatus with gluing to be used in the so-called tandem operation, in which the two labelling apparatus label every second container in an alternate manner. These two solutions, however, incur considerable costs.
The object of the invention is therefore to provide a labelling apparatus and a labelling process for the labelling of containers as well as a plant for the treatment of containers, in which faults of an apparatus arranged upstream of the labelling apparatus or faults or delays in the gluing of strips of labels do not lead to a stoppage of the labelling apparatus and thus of the plant